Antistatic fiber

ABSTRACT

An improved antistatic fiber of polyamide, polyester, polyurea, polyurethane or polysulfonamide is prepared by uniformly dispersing an antistatic additive consisting of a chain-extended propylene oxide-ethylene oxide copolymer based on a diamine, in the fiber-forming polymer, forming the fiber by conventional methods, then applying to the fiber a coating of the antistatic additive. The improved antistatic fiber is especially useful for carpet manufacture. In carpet use, the antistatic additive included in the fiber improves with age, whereas the additive externally added is gradually abraded off in use; the net result is a relatively stable antistatic capability.

United States Patent [191 Wincklhofer et a1.

ANTISTATIC FIBER Inventors: Robert Charles Wincklhofer,

Richmond; Judd Leonard Schwartz, Chester, both of Va.

Allied Chemical Corporation, New York, NY.

Filed: Mar. 5, 1973 Appl. No: 337,777

Assignee:

References Cited UNITED STATES PATENTS 12/1955 Cohen 117/1395 CQ 3/1961 Macura et a1 l. 117/1395 A 1 Mar. 25, 1975 3,333,983 8/1967 Sellet 117/1395 UA 3,470,267 9/1969 Litt et al. 3,657,386 4/1972 Weedon et al 260/775 A Primary ExaminerWilliam D. Martin Assistant Examiner-Theodore G. Davis Attorney, Agent, or Firm-Fred L. Kelly [5 7] ABSTRACT An improved antistatic fiber of polyamide, polyester, e qa seei yre h as 9 .pe ys te tatnisis c is pr pared by uniformly dispersing an antistatic additive consisting of a chain-extended propylene oxideethylene oxide copolymer based on a diamine, in the fiber-forming polymer, forming the fiber by conventional methods, then applying to the fiber a coating of the antistatic additive. The improved antistatic fiber is especially useful for carpet manufacture. ln carpet use, the antistatic additive included in the fiber improves with age. whereas the additive externally added is gradually abraded off in use; the net result is a relatively stable antistatic capability.

4 Claims, No Drawings 1 2 ANTISTATIC FIBER where R is a difunctional radical derived from aro REFERENCE To RELATED APPLICATIONS matic, heterocyclic, cycloaliphatic or aliphatic hydrocarbons or combinations of them. Preferably, the ethyl- This application is related to U.S. application s ene oxide moiety makes up 10 to 90% of the molecular No. 294,971, filed Oct. 11, 1972 by Gene C. Weedon 5 weight of the tetrol compound. The improved antistatic and Lamberto Crescentini. fiber is especially useful for carpet manufacture.

BACKGROUND OF THE INVENTION In carpet use, the antistatic additive included in the fiber improves with age, whereas the additive exter This in enti n rel to a pr f h meltnally added is gradually abraded off in use; the net respinning of a filamentary structure from a synthetic i i a relatively stable antistatic capability. polymer such as polyamide, polyester, polyurea, poly- The chain extended compound is added to the polyurethane peiysuifehamide More Particularly, it is mer in amounts from about 1 to about 12% by weight, concerned with an improved process for the formation f bl bout 2 to about 10% by weight. The yarn Of an improved antistatic filament, y Or the iike y is preferably coated with between about 0.05 and about melt-spinning a synthetic linear fiber-forming polymer l5 6% by weight, preferably 0.1 to 3% by weight, based on containing an antistatic additive, and thereafter treatth finished yarn, of the chain-extended compound. ing the fibrous structure with an antistatic composition Th h inxtended compound is preferably applied to to improve the antistatic P p the yarn in the form of a solution in a suitable solvent it has been Suggested that the utility of synthetic such as water, benzene, or ethyl alcohol; concentrabers could be increased and their properties, in particutions between about 0,1 a d about 10% are suitable. their antistatic Properties, Could be improved if a The coated yarn may be heated, if desired, to cause volpolyalkylene ether of high molecular weight is included ili i f h lv t, in the p y More speeitieaiiyi it is diseiosed ih The tetrol compound which is chain-extended for use Pat 3,475,898 to Megan and sharkey to use p yas an antistatic additive in this invention is fully de (ethylene-Propylene)ether g y for this p p scribed in U.S. Pat. No. 2,979,528 to Lundsted, 215- More recently, discloses that signor to Wyandotte. These tetrol compounds are comcertain propylene oxide-ethylene oxide copoly mercially available as tetronic series block copolymers based on ethylene diamine are useful in preparation of h i molecular i ht between 1,650 and over an antistatic fiber Of Th present invention eries varies in length 0f poly(oxyethy is an improvement upon the invention disclosed in U.S. 3O lene) h i d polymxypropyiene) h in, A 3 nnd 4 Pu O- 3, I digit code number indicates the molecular composi- SUMMARY OF THE INVENTION tion. When four digits are employed, the first two explain the average molecular weight of the hydrophobe Applicants have discovered that a superior antistatic (polywxypropylene) l e) b nches on the fiber of p y t Polyester, p y i Polyurethane alkylene-diamine). When three digits are used only the or polysulfonamide can be prepared by uniformly disfirst number serves this purpose. The last digit of each persing in the fiber-forming polymer an antistatic addid n mber represents the weight percentage of hytive consisting ofa chain-extended tetrol based on a didrophilic (poly(oxyethylene)) units to the nearest 10%. amine, forming the tihel' y Conventional methods, and The tetrol compounds in the examples are described then applying to the fiber a coating of the antistatic ad- 40 hi ditive. chain-extended tCtl'Oi based on a diamine AS diamines upon which the [en- 15 are based in adis a predominantly branched ch n-e te p ly dition to ethylene diamine, diamines of the hydrocar- Of the reaction product Of a et mp n P bon containing 1 to 13 carbon atoms, preferably the sented by the formula: lower alkyl diamines, where the lower alkyl radical C'H3 (III-I3 H(OCH2'CH )y(OCHCH- c (CH CHO) (CH CH O) H cn NR-= CH t I i H (OCH2CH2) z (OCHCH2) d (CHZCHO) b (CH2CH2O)WH where a, b, c, d, w, .r, y, and z are each a whole number contains l6 carbon atoms, can be used.

and R is a difunctional radical from a hydrocarbon con- The polyepoxy coupled compounds can be prepared taining l to 13 carbon atoms, preferably a lower alkyl by the method taught in British Pat. No. 793,9l5, Exaliphatic hydrocarbon containing 1 to 6 carbon atoms, ample I. The other classes of compound can be simiand at least one compound selected from thegroup larly prepared, as in Example 10 in U.S. Pat. No

consisting of diepoxides and compounds which yield 3,009,884. the following divalent radicals: Typical of the acids and their esters to provide the i chain-extending difunctional radical are the dialkyl o O phthalic, isophthalic or terephthalic esters. such as dimethyl terephthalate and adipic, phthalic, terephthalic, C, RI C and sebacic, glutaric, pimelic, isocinchomeronic acids and their esters.

O H H 0 Typical of the polyepoxy compounds which provide the difunctional or divalent compounds. used to chain- C-N'-R'-N-C- extend the tetrols based on diamines, are those polyepoxy compounds described in British specification No. 793,)l to Union Carbide on page 2. linc 48 to line l2] as follows:

The organic polyepoxy compounds suitable for use in preparing the polymeric products of this invention are organic compounds having as the sole reactive groups under the conditions of this reaction, at least two epoxy groups. By this we mean to exclude compounds containing carboxyl, hydroxyl, phenolic hydroxyl, amino, amido, imido and mercapto groups, which have been found to be reactive under the conditions of this reaction with epoxy groups of the polyepoxy compound or with the hydroxyl groups and alkali metal alcoholate groups of the polyoxyalkylene glycol, and thus will interfere with the desired condensation. These polyepoxy compounds free of such interfering groups can be aliphatic, cycloaliphatic and aromatic, and can contain non-interfering substituent groups such for example as alkyl, aryl, organic ester, phosphate ester, halogen and cyano groups without interfering with the condensation. Olefinic unsaturation in the polyepoxy compound can also be present.

The preferred organic polyepoxy compounds are the aliphatic, cycloaliphatic and aryl substituted aliphatic compounds having as the sole reactive groups under the conditions of the reaction. at least two epoxy groups. and wherein oxygen is present only in oxirane, ether and ester arrangement. Particularly preferred are the diepoxy compounds consisting only of carbon, hydrogen and oxygen, wherein oxygen is present only in oxirane, ether and ester arrangement, and wherein the epoxy groups are terminal groups of an aliphatic or aryl substituted aliphatic compound or where the epoxy group or groups include adjacent carbon atoms of a cycloaliphatic ring. Representative of these preferred compounds are butadiene diepoxide, diglycidyl ether, the diglycidyl ether of 2,2-bis(4-hydroxyphenyl)- propane, 4-vinyl-cyclohexene diepoxide, dicyclopentadiene diepoxide, bis(2,3-epoxycyclopentyl)ether, ethylene glycol bis(3,4-epoxy-methylcyclohexanecarboxylate) and the 3,4-epoxy-methylcyclohexylmethyl 3,4-epoxy-methylcyclohexanecarboxylate.

It is to be understood that the invention is not limited to the foregoing compounds alone and a variety of organic polyepoxy compounds can be used. While it is preferred that the epoxy groups be terminal groups or include adjacent carbon atoms of a cycloaliphatic ring, aliphatic and substituted aliphatic compounds having adjacent carbon atoms of the epoxy group as adjacent intermediate carbon atoms of a linear chain may be used. However, compounds having such internal epoxy groups react somewhat slower compared with those compounds having terminal epoxy groups.

A mixture of two or more polyepoxy compounds can be used in the practice of this invention, or if desired, the polyoxyalkylene glycol can be reacted successively with different polyepoxy compounds to obtain these polymeric products. I

These polyepoxy compounds serve both as chain extenders between polyalkylene glycol chains and as cross-linking agents. According to our experience, pri mary hydroxyl groups of the polyoxyalkylene glycol react preferentially with the epoxy groups to link up the polyglycol chains, creating secondary hydroxyl groups upon opening of the epoxide ring.

Also useful to form chain-extending divalent radicals are the aromatic or aliphatic diisocyanates, having a structure OCN-R'-NCO, where R is defined as above.

The antistatic fiber of this invention may also contain conventional fiber additives such as antioxidants, stabilizers, delusterants, dyeing assists, and colorants.

DESCRIPTION OF THE PREFERRED EMBODIMENT in order to demonstrate the invention, the following examples are given. They are provided for illustrative purposes only and are not to be construed as limiting the scope of the invention, which is defined by the appended claims. parts and percents are by weight unless otherwise indicated. Parts Following is a list of properties of tetrol compounds identified by Tetronic numbers in the Examples.

A glass reactor equipped with a heater and stirrer was charged with a mixture of 1,520 grams of ecaprolactam and grams of aminocaproic acid. The mixture was then flushed with nitrogen and was stirred and heated to 255C. over a one hour period at atmospheric pressure to produce a polymerization reaction. The heating and stirring was continued at atmospheric pressure under a nitrogen sweep for an additional four hours in order to complete the polymerization. Nitrogen was then admitted to the glass reactor and a small pressure was maintained while the polymer was extruded from the glass reactor in the form of a polymer ribbon. At this time, grams of antistatic additive as mixed into the polymer, the antistatic additive being the reaction product of Tetronic 1504 and dimethyl terephthalate (DMT) in a l to 0.9 mol ratio. This additive is soluble in toluene and water and has a melt viscosity of 10,000 centipoises at C. The antistatic additive was mixed into the polymer by blending molten polymer and antistatic additive in a static mixer to produce a uniform dispersion of antistatic additive in the extrudate. The polymer ribbon was subsequently cooled, pelletized using a Wiley Mill, washed and then dried. The polymer was a white solid having a relative viscosity of about 50 to 60, as determined at a concentration of 1 1 grams of polymer in lOO ml. of 90 percent formic acid at 25C. (ASTMD-789-62T).

EXAMPLE 2 Polymer pellets prepared in accordance with Example l and containing the antistatic agent were melted at about 285C. and then melt extruded under pressure of l,500 psig to a 70-orifice spinnerette, each of the orifices having a diameter of 0.0l8 inch to produce a fiber having about 4.500 denier. The fiber was collected at about 1,000 feet per minute and was drawn at about 4 times the extruded length to produce yarn having a denier of about 1,050. This yarn will hereinafter becall ed Yarn A A control yarn containing no antistatic agent was prepared in the same manner as described above. This yarn will hereinafter be called Yarn B.

The yarns were textured using a steam jet and then two-plied by twisting two ends together with a 1% S twist. The yarns were tufted into a level loop 20 02. carpet at about 6.5 stitch rate, about 9/32 to 10/32 inch pile height, dyed and latexed. Static buildup of the carpet was tested by measuring the electrostatic voltage buildup on a person walking with a series of steps on a piece of carpet according to the standard CR1 Walk Test for static propensity in carpets, also labeled AATCC 134-1969. Carpet was conditioned at 70F. at 20 percent relative humidity. Results are shown in the following Table.

' Static Walk Carpet Test Made with Yarn A 6.1 KV Made with Yarn B 14.1 KV

EXAMPLE 3 cient solution was applied to the carpet samples to pro-' vide 3, l and 0.3% of the antistatic additive as a coating on the fibers of the dried carpet. A control carpet sample was prepared from Yarn A in the same manner except that water was used in place ofthe solution of antistatic additive. Static buildup'of the carpet samples was tested in accordance with the procedure described in Example 2. Results are shown in the following Table.

Static Carpet Walk Test Yarn A with no antistatic coating 6.1 KV Yarn A with 0.3% antistatic coating 0.5 1(V Yarn A with 1.0%

antistatic coating 0.5 KV Yarn A with 3.071

antistatic coating 0.5 KV

Similar excellent results were obtained when the antistatic additive used was of similar structure to that described in Example 1 except that the tetrol starting compound was Tetronic 908, Tetronic 1302 or Tetronic 1506.

Additional tests showed that the antistatic additive included in the fiber improved in antistatic capability with age, whereas the antistatic additive externally added was gradually abraded off in use; the net result was a relatively stable antistatic capability.

EXAMPLE 4 The procedure of Example 1 was followed with a material of similar structure to that described except that the DMT/polyether mol ratio was 1.0 and melt viscosity was about 17,500 centipoises at 100C. Carpet samples prepared, coated with the instant antistatic additive, then tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 5 A glass reactor equipped with a heater and stirrer was charged with a mixture of 1,520 grams of ecaprolactam and grams of aminocaproic acid. The mixture was then flushed with nitrogen and was stirred and heated to 255C. over a 1 hour period at atmospheric pressure to produce a polymerization reaction. The heating and stirring was continued at atmospheric pressure under a nitrogen sweep for an additional four hours in order to complete the polymerization. During the last 30 minutes of the polymerization, 60 grams of the antistatic additive of Example 1 was added to the polycaproamide and stirring was continued to thoroughly mix the antistatic agent throughout the polymer. Nitrogen was'then admitted to the glass reactor and a small pressure was maintained while the polymer was extruded from the glass reactor in the form of a polymer ribbon. The polymer ribbon was subsequently cooled, pelletized using a Wiley Mill, washed and then dried. The polymer was a white solid having a relative viscosity of about 55 to 60, as determined at a concentration of 11 grams of polymer in 100 ml. of percent formic acid at 25C. (ASTMD-78962T).

Carpet samples prepared from this polymer, treated with the instant antistatic additive and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 6 A glass reactor equipped with a heater and stirrer was charged with a mixture of 1,520 grams of ecaprolactam, 80 grams of aminocaproic acid, 60 grams of an antistatic additive obtained from the reaction product ofTetronic 1504 and dimethyl terephthalate in a 1 to 0.7 mol ratio. The additive was soluble in water and toluene, and had 1,600 centipoise melt viscosity at C. The mixture was then flushed with nitrogen and was stirred and heated to 255C. over a 1 hour period at atmospheric pressure to produce a polymerization reaction. The heating and stirring was continued at atmospheric pressure under a nitrogen sweep for an additional 2.3 hours in order to complete the polymerizatron.

Nitrogen was then admitted to the glass reactor and a small pressure was maintained while the polymer was extruded from the glass reactor in the form of a polymer ribbon. The polymer ribbon was subsequently cooled, pelletized using a Wiley Mill, washed and then dried. The polymer was a white solid having a relative viscosity of about 55 to 60. as determined at a concentration of 1 1 grams of polymer in 100 ml. of 90 percent formic acid at 25C. (ASTMD-789-62T).

Carpet samples prepared from this polymer. treated with the instant antistatic additive, and tested in accordance with Examples 2 and 3. showed a static build-up of less than 0.5 K.V.

EXAMPLE 7 The procedure was that of Example 6 except that 90 grams of the antistatic additive was used instead of 60 grams. Carpet samples prepared from this polymer, treated with the instant antistatic additive, and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 8 The procedure was that of Example 1 except that 60 grams of an antistatic additive obtained from the reaction of Tetronic 1504 and methylene bis(4-cyclohexyl isocyanate) were used. This material had an ethylene oxide content of about 40% and a diisocyanate/- polyether mol ratio of 0.9. Carpet samples prepared from this polymer, treated with the instant antistatic additive, and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 9 The procedure was that of Example 1 except 60 grams of an antistatic material derived from the reac- By antistatic" fiber is meant fibers that will pass the cling test and the shuffle test as described in US. Pat. No. 3,657,386. By *fiber" is meant multifilamcnt yarn, monofilament, and all the known physical forms of synthetic fibers. By "polyamide" is meant the polymers made by condensation of diamines with dibasic acids or by polymerization of lactams or amino acids, resulting in a synthetic resin characterized by the recurring group -CONH. By ethylene oxide moiety is meant the portion of the chemical molecule (CH C- We claim:

1. An antistatic fiber selected from the group consisting of polyamide, polyester, polyurea, polyurethane, and polysulfonamide, said fiber containing between about 1 and about 12% by weight of an antistatic additive consisting of a predominantly branched, chainextended polymer of the reaction product of a tetrol compound represented by the formula:

tion of Tetronic 1504 and the diglycidyl ether of 2,2 bis(4-hydroxyphenyl)propane was used. This material had an ethylene oxide content of about 40% and a ratio of the diglycidyl ether of 2,2-bis(4-hydroxyphenyl)- propane to polyether of 0.9. Carpet samples prepared from this polymer, treated with the instant antistatic additive, and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 10 The procedure was that of Example 9 and antistatic additive was similar except that the tetrol compound molecule had 60% ethylene oxide (Tetronic 1506). Carpet samples prepared from this polymer, treated with the instant antistatic additive, and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

EXAMPLE 1 l Ninety-four parts of polyhexamethylene adipamide and six parts of the antistatic material of structure of Example 1 are melt blended by mixing the additive with the molten polyamide at about 285C. The melt is extruded from a spinneret and the fibers are drawn as described in Example 2. Carpet samples prepared from this fiber, treated with the antistatic additive of Example 9, and tested in accordance with Examples 2 and 3, showed a static build-up of less than 0.5 K.V.

DISCUSSION In additional tests it was determined that the molecular weight of the antistatic compound is preferably between about 9,000 and about 50,000, the ethylene oxide moieties desirably making up about 20 to about 80% ofthe molecular weight of said compound. Preferably, the antistatic compound has a melt viscosity of 1.600 to 17.500 centipoises at 100C.

where a, b, c, d, w, x, y, and z are each a whole number and R is a difunctional radical from a hydrocarbon containing 1 to 13 carbon atoms, reacted with at least one chain-extending compound selected from the group consisting of diepoxides and compounds which yield the following divalent radicals:

O 0 II H H II where R is a difunctional radical derived from aromatic, hetrocyclic, cycloaliphatic or aliphatic hydrocarbons or combinations of them, said fiber having a coating thereon of between about 0.05 and about 6% by weight of said antistatic additive, based on the weight of the finished fiber, said antistatic additive having a melt viscosity of 1,600 to 17,500 centipoises at 100C.

2. The antistatic fiber of claim 1 wherein R is a difunctional radical from a lower alkyl aliphatic hydrocarbon compound containing 1 to 6 carbon atoms.

3. The polyamide fiber of claim 1 wherein the ethylene oxide moieties make up about 10 to about of the molecular weight of said tetrol compound and the fiber contains between about 2 to about 10% of the antistatic additive.

4. The polyamide fiber of claim 3 wherein the fiber has a coating thereon of between 0.1 and 3% by weight of said antistatic additive. based on the weight of the finished fiber. 

1. AN ANTISTATIC FIBER SELECTED FROM THE GROUP CONSISTING 1 POLYAMIDE, POLYESTER, POLYUREA, POLYURETHANE, AND POLYSULFONAMIDE, SAID FIBER CONTAINING BETWEEN ABOUT 1 AND ABOUT 30 % BY WEIGHT OF AN ANTISTATIC ADDITIVE CONSISTING OF A PREDOMINANTLY BRANCHED, CHAIN-EXTENDED POLYMER OF THE REACTION PRODUCT OF A TETROL COMPOUND REPRESENTED BY THE FORMULA:
 2. The antistatic fiber of claim 1 wherein R is a difunctional radical from a lower alkyl aliphatic hydrocarbon compound containing 1 to 6 carbon atoms.
 3. The polyamide fiber of claim 1 wherein the ethylene oxide moieties make up about 10 to about 90% of the molecular weight of said tetrol compound and the fiber contains between about 2 to about 10% of the antistatic additive.
 4. The polyamide fiber of claim 3 wherein the fiber has a coating thereon of between 0.1 and 3% by weight of said antistatic additive, based on the weight of the finished fiber. 